• Membrane Journal
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• v.16 no.2
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• pp.115-122
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• 2006

In this study the membrane preparation and water vapor permeation of the hydrophilic polymer materials, polyaminosiloxane and polyhydroxylsiloxane, used as the coating materials for the preparation of asymmetric flat and hollow fiber membranes were investigated. And the water vapor permeation towards air permeation and their permselectivity were intensively studied for the resulting Resin A/Resin C (coupling agent) and Resin B/Resin C membranes. The water vapor permeability for 3 wt% Resin C introduced into Resin A (Resin A/Resin C) membrane was higher than for 1 and 5 wt% membranes and also water vapor permeability increased with increasing operating temperatures. In addition, at this content of 3 wt% Resin C, the absorption capability became maximum through dynamic equilibrium absorption experiment. Water vapor permeability, 43578 Barrer (1 Barrer = $10^{-10}cm^3(STP){\cdot}cm/cm^2{\cdot}s{\cdot}cmHg$) and 53000 Barrer, and the selectivity of $P(H_2O)P(Air)$, 101.3 and 102.6 were shown at 25 and $35^{\circ}C$, respectively.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.545-551
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• 1996

Water-vapor transmission rate and water-vapor permeability of carrageenan-based edible film with three different thicknesses of 0.05, 0.08 and 0.11 mm were measured to investigate the potential applicability of the films to powder foods at five different temperatures (20, 25, 30. 35 and $4^{\circ}C$) and three different relative humidities (50. 70 and 90% RH). Water-vapor transmission rate of the carrageenan-based film was gound to be 2.3 times higher than that of polyethylene (PE) film and water-vapor permeability of the film was 45-230 times higher than that of PE film. Water-ydpor permeability of the film seemed to increase linearly with the film thicknees like other hydrophilic edible films. Water-vapor transmission rate were found to be dependent on the temperature. Activation energies of the water-vapor transmission rate of the film were found to be between 7.898 and 12.8702 kj/mol depending on the film thickness. The water-vapor transmission rate of the film showed the typical kinetic compensation effect between activation energies and preexponential factors. which was proved by the linear increase in the value of logarithms of preecponential factor.

• Membrane Journal
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• v.13 no.3
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• pp.154-161
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• 2003

We measured the permeation characteristics of water with the hydrophobic PTFE membranes dependent on water temperature to confirm the separation of oxygen isotopes using Air Gap Membrane Distillation (AGMD) and Vacuum Enhanced Membrane Distillation (VEMD). Isotopic concentrations of $H_2^{16}O$ and $H_2^{18}O$ of the permeated water vapor were measured by Diode Laser Absorption Spectroscopy. Concentrations of the heavy oxygen isotopes in the permeated water vapor were decreased. Isotope separation coefficients for the hydrophobic PTFE membranes were 1.004∼1.01 depending on the experimental conditions. We observed the effects of air in membrane pores on the oxygen isotope separation. Isotope separation coefficients for the hydrophobic PTFE membranes without air in pores are higher than those for the membrane with air in pores.

• Membrane Journal
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• v.15 no.4
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• pp.330-337
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• 2005

Water selective silica membranes were prepared fur use as membrane reactor for synthesis of dimethyl ether (DME) by methanol dehydration. Silica membranes formed on a Porous SUS tube by ultrasonic spray Pyrolysis (USP) and chemical vapor deposition (CVD) using tetraethoxysilane (TEOS) as precursor. The CVD-derived membranes formed higher level of trade-off line between water permeance and water/methanol selectivity than that of the USP-derived membranes. The membrane reactor possessing water permeance of $1.2\times10^{-7}\;mol\;{\cdot}\;m^{-2}\;{\cdot}\;S^{-1}\;{\cdot}\;Pa^{-1}$ and water/methanol selectivity of 10 exhibited increase in methanol conversion of about $20\%$ comparing to conventional reactor system. These findings led us to conclude that the dehydration membrane reactor simultaneously separating the water vapour produced in the reaction zone was effective in increasing the reaction conversion.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.582-586
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• 1999

The processing conditions for producing and edible alginate film from sea tangle were investigated by measuring water vapor permeability (WVP), tensile properties and colors of film. The alginates were extracted with $3\%$ sodium carbonate ($Na_2CO_3$) solution for 5 hrs, and the alginate films were prepared with extracted sodium alginates, D-gluconic acid lactone, $CaCO_3$ and various plasticizers, As the concentration of alginate in making the film was increased, the WVP and elongation of the film were decreased and the tensile strength was increased. The higher amount of plasticizer showed the higher WVP and elongation, and the order of various plasticizers in increasing the WVP and elongation of the film was glycerol, polyethylene glycol, and sorbitol. The addition of sorbitol in the film showed the highest value (89.57) in lightness of Hunter color system and the film added polyethylene glycol had the highest values (-1,12 and 11.4) in redness and yellowness.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.664-668
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• 1999

The extracting conditions of alginates from sea tangle were evaluated by measuring water vapor permeability (WVP) and tensile properties of alginate film to obtain basic data of making an edible and biodegradable film. The alginates were extracted with $1\%,\;3\%$ and $5\%$ sodium carbonate ($Na_2CO_3$) for 1, 3, 5 and 10 hours, and the alginate film was made with various plasticizers. The higher concentration of $Na_2CO_3$ solution showed the lower viscosity and polymerization degree of alginate and the film prepared with alginates having low viscosity showed the higher WVP. The extracting hours had little effect on the WVP and the elongation of alginate film, but the polymerization degree of alginates directly affected the tensile strength of the film. The addition of sorbitol and polyethylene glycol as a plasticizer lowered the WVPs and the elongation of alginate film.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.225-226
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• 2013

Existing polyurethane membrane waterproofing has been raised defects such as heaving. Therefore, We will be utilizing as the basic experimental data by the water vapor permeability test to the air cell structure of ultra rapid harding membrane waterproofing using the static mixing system in this study.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.04a
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• pp.65-66
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• 1996

투과증발법은 상부에 액체공급액이 반투과막과 접촉하고 있고 하부에 진공에 가까운 낮은 압력을 걸어줌으로써 투과물이 수증기로 제거되는 막공정의 하나이다. 막을 통한 분리는 혼합물의 각 성분이 막내에서 다른 용해도와 확산도를 가지고 있기 때문에 발생한다. 이 공정의 지배적인 전달 메카니즘은 용해-확산 모델을 기초로 하고 있기 때문에 전형적으로 투과증발막은 대개 미세다공성 지지체에 얇은 선택성을 가진 재료를 입힌 복합막을 사용한다. 본 연구의 목적은 선택성을 가진 상부층막이 키토산인 복합막에서 지지체 구조의 영향을 살펴보고 키토산 복합막에 대한 물-에탄올 분리에 대해 최적의 모델을 찾는 것이다. 투과증발막소재로서의 키토산은 친수성기를 가지고 있으므로 물과 알코올의 분리에서 물만을 선택적으로 흡수하여 투과시키는 우수한 성능을 지니고 있으나 더욱 효과적인 막성능을 발휘하기 위해서는 지지체의 역할 및 막성능에 영향을 끼치는 여러 가지 인자들을 고려해서 막을 설계하는 것이 필요하다. 여기서는 상부층의 막두께, 지지체의 특성, 피드 농도 등을 변화시켜 가장 적당한 모델을 예측하였다.

• Membrane Journal
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• v.23 no.3
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• pp.237-244
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• 2013

We fabricated several composite membranes with selectively permeable performance designed to facilitate water vapor transport and resist DMMP vapor permeation. Materials for selective permeable membrane were based on polyvinyl alcohol and functional polymer containing basic functional group. With these materials, we characterized selectively permeable performance to identify next-generation material with chemical-biological protective capability. Results showed that polyvinyl alcohol (PVA)/polyethyleneimine (PEI) materials possessed performance with superior water vapor permeation ($2,200{\sim}2,900g/m^2/day$) and protective capability against DMMP vapor ($47g/m^2/day$).

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.494-499
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• 2001

To determine optimal conditions for preparing protein isolate film from fish meal, the water vapor permeability (WVP), tensile properties and solubility of fish meal proteinisolate (FMPI) film were measured. FMPI was extracted from fish meal under conditions of various extraction times at $60^{\circ}C$. Extracting time little affected to WVP of FMPI film. The film added with glycerol as plasticizer showed higher WVP than sorbitol added. As extraction time increased up to 1 hr, tensile strength and elongation were increased. While in more extracting time than 1 hr, increasing extracting time made tensile strength and elongation showed negative correlations. The correlation of soluble protein amount and tensile strength showed higher value ($r^{2}=0.83$) than that of elongation ($r^{2}=0.62$).